To borrow an example from here in Zambia. In the 1960s Zambia used to have a textile industry that produced clothes sold in the region. That's disappeared because it couldn't compete with cheap imports from Asia and second-hand clothes from the west. A bit of protectionism would be required to get that industry started again, and with enough investment, it could eventually hopefully become competitive without protectionism.

Some protectionism helps poorly developed industries grow locally until they're competitive enough to compete globally (eg postwar Japan). However, other protectionism maintains inefficient industries at the expense of poor people in other countries who could do the same job cheaper (eg US agriculture)

>However, other protectionism maintains inefficient industries at the expense of poor people in other countries who could do the same job cheaper

...thus protecting the nation's citizens from having their jobs exported overseas. How is that not government protecting the nation's best interests?